Flashcards in Chapter 9 Textbook notes Deck (96):
What happens during inspiration?
Also called inhalation (breathing in), air is conducted from the atmosphere to the lungs by a series of cavities, tubes, and openings
What happens during expiration?
Also called exhalation (breathing out), air is conducted from the lungs to the atmosphere
Another term for breathing that includes both inspiration and expiration.
What happens once ventilation occurs?
The respiratory system depends on the cardiovascular system to transport oxygen (O2) from the lungs to the tissues and carry carbon dioxide (CO2) from the tissues to the lungs.
Why is gas exchange necessary?
Because the cells of the body carry out cellular respiration to make energy in the form of ATP.
What happens during cellular respiration?
Cells use up O2 and produce CO2. The respiratory system provides these cells with O2 and removes CO2
What is involved in the upper respiratory tract?
1. Nasal cavity
Filters, warms, and moistens air
Passageway where pathway for air and food cross
Space between the vocal chords; opening to larynx
What are the lower respiratory tracts?
(Windpipe); passage of air to bronchi
Passage of air to lungs
Passage of air to alveoli
Contains alveoli (air sacs); carries out gas exchange
Skeletal muscle; functions in ventilation
What are the three parts of pharynx (throat)?
1. Nasopharynx, where the nasal cavities open above the soft palate
2. Oropharynx, where the oral cavity opens
3. Laryngopharynx, which opens into the larynx
Form a protective ring at the junction of the oral cavity and the pharynx
What cells do the tonsils contain?
Lymphocytes, which protect against invasion of inhaled foreign antigens
Primary defense during breathing
What type of cells in the tonsils are prepared to respond to antigens that may subsequently invade internal tissues and fluids?
B cells and T cells
In the pharynx, what passages lie parallel to each other and share a common opening in the laryngopharynx?
Air passage and food passage
When is the esophagus open?
It is normally closed and opens only when a person swallows
What may be done when a passageway remains blocked by food?
A cartilaginous structure that serves as a passageway for air between the pharynx and the trachea
Why is the larynx called the voice box
Because is houses the vocal cords
Mucosal folds supported by elastic ligaments
The slit between the vocal cords
How do we produce sound?
When air is expelled through the glottis, the vocal cords vibrate, producing sound
Loudness or intensity of the voice depends upon
The amplitude of the vibrations-the degree to which the vocal cords vibrate
A flap of tissue that prevents food from passing into the larynx
Its walls consist of connective tissue and smooth muscle reinforced by C-shaped cartilaginous rings
What do the rings in Trachea do?
Prevent it from collapsing
Lies anterior to the esophagus
What is the role of goblet cells?
produce mucus, which traps debris in the air as it passes through the trachea
If the trachea is blocked because of illness or the accidental swallowing of a foreign object, a breathing tube can be inserted by way of an incision made in the trachea. This tube acts as an artificial air intake and exhaust duct.
What divides into the right and left primary bronchi?
What leads into the right and left lungs?
What happens as bronchial tubes divide?
As the bronchial tubes divide and subdivide, their walls become thinner, and the small rings of cartilage are no longer present
Where do each of the bronchiole lead to?
An elongated space enclosed by a multitude of air pockets or sacs called alveoli
Where are the lungs located?
The lungs are paired, cone shaped organs in the thoracic cavity
What is in the center of the thoracic cavity?
Trachea, heart, thymus, and esophagus
The muscle that separates the thoracic cavity from the abdominal cavity.
Each lung is enclosed by?
Pleurae: Two layers of serous membrane that produces serous fluid.
Tendency of water molecules to cling to one another due to hydrogen bonding between molecules
Holds the two pleural layers together
Each alveolar sac is surrounded by?
Where does gas exchange occur?
Between air in the alveoli and blood in the capillaries
Describe how O2 and CO2 exchange gases
O2 diffuses across the alveolar wall and enters the bloodstream, and CO2 diffuses from the blood across the alveolar wall to enter the alveoli
The alveoli of human lungs are lined with?
A surfactant, a film of lipoprotein that lowers the surface tension of water and prevents the alveoli from closing
How is infant respiratory distress syndrom treated?
By surfactant replacement therapy
Ventilation, or breathing, as two phases
Inspiration (inhalation), moves air into the lungs
and expiration (exhalation), moves air out of the lungs
True or False: Normally, there is a continuous column of air from the pharynx to the alveoli of the lungs?
How do lungs adhere to the thoracic wall?
By way of the pleura
Active phase of ventilation
Lung volume/air pressure
As the lung volume increases, the air pressure within the alveoli decreases, creating a partial vacuum
Passive phase of breathing
During this, the diaphragm and external intocostal muscles relax
Why do the lungs recoil?
Because the surface tension of the fluid lining the alveoli tends to draw them closed
Maximum inspiratory effort involves what muscles?
Back, chest, and neck
Can expiration be forced?
How can we increase expiration?
By contracting the abdominal and thoracic muscles
How can we increase inspiration?
By expanding the chest and also by lowering the diaphragm to the maximum extent possible
Breathing is controlled in two ways
Nervous and chemical control
The rhythm of ventilation is controlled by a?
Respiratory control center located in the medulla oblongata of the brain
What does the respiratory control center do?
Automatically sends out nerve signals to the diaphragm and the external intercostal muscles of the rib cage, causing inspiration to occur
What happens when the respiratory center stops sending nerve signals to the diaphragm and rib cage
The muscles relax and expiration occurs
Is it possible to voluntarily change our breathing patterns?
Sensory receptors in the body that are sensitive to chemical composition of body fluids
What can cause breathing to speed up?
Two sets of of chemoreceptors sensitive to pH can cause breathing to speed up
Where are two chemoreceptors located?
A centrally placed set is located in the medulla oblongata of the brain stem
The peripherally placed set is in the circulatory system
When the pH of the blood becomes more acidic (decreases), the respiratory center?
Increases the rate and depth of breathing
What happens when a person tries to hold their breath?
The respiratory center, stimulated by the chemoreceptors, is able to override a person's voluntary inhibition of respiration. Breathing resumes, despite attempts to prevent it
Respiration includes the exchange of
Gases not only in the lungs but also in the tissues
Principe of diffusion governs
Whether O2 or CO2 enters or leaves the blood in the lungs and in the tissues
The amount of pressure each gas exerts is called its
What happens if the partial pressure of O2 differs across a membrane?
Oxygen will diffuse from higher to lower partial pressure
Refers to the exchange of gases between air in the alveoli and blood in the pulmonary capillaries
Where does CO2 diffuse?
CO2 diffuses out of the plasma into the lungs
Most of the CO2 is carried in
Plasma as bicarbonate ions (HCO3-)
Speeds the breakdown of carbonic acid in RBCs
The enzyme carbonic anhydrase
O2 diffuses into plasma and then into RBC's in the lungs
Refers to the exchange of gases between the blood in systemic capillaries and the tissue cells
Blood entering systemic capillaries is what color and why?
Bright red color because RBC's contain oxyhemoglobin
Oxyhemoglobin naturally gives up?
What happens after oxyhemoglobin gives up O2?
It diffuses out of the blood into the tissues
Carbon dioxide diffuses
into the blood from the tissues
When is carbon dioxide produced?
During cellular respiration and collects in tissue fluid
After CO2 diffuses into the blood?
Most enters the RBC's, where a small amount is taken up by hemoglobin, forming carbaminohemoglobin (HbCO2)
What is the color of blood that leaves the systemic capillaries
Dark maroon color because RBC's contain reduced hemoglobin
Where can the upper respiratory infections (URIs) spread?
From the nasal cavities to the sinuses, middle ears, and larynx
Develops when nasal congestion blocks the tiny openings leading to the sinuses
Lower respiratory tract disorders include
Infections, restrictive pulmonary disorders, obstructive pulmonary disorders, and lung cancer
An infection of the primary and secondary bronchi